计量科学与技术

Design and Implementation of Total Station Performance Evaluation and Early Warning System: Application of a Fuzzy Comprehensive Evaluation Method

SHI Lei, WANG Guanjun, LI Juan, YU Fang, JIN Hanle, LIU Lixia, TAN Yun, LI Qixiong, XIAO Yin

2024, 68(9): 3-12. doi: 10.12338/j.issn.2096-9015.2024.0111

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Abstract:
Measuring institutions generate substantial verification data during periodic inspections of measuring instruments, but the immense economic and social value hidden within this data remains largely untapped. Currently, the evaluation of measuring instrument performance is limited to assessing the quality or metrological performance of individual instruments. This study proposes a generalizable method for evaluating the performance and predicting the failure of measuring instruments, using the vast amount of data generated from total station verifications. The process begins with analyzing and processing the verification data of total stations. Subsequently, the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method is employed to comprehensively evaluate the performance of individual total stations. The Vague set decision theory is then utilized to assess the overall quality of total stations from various manufacturers. Early warning analysis of the total stations' validity is conducted using the maximum permissible error and slope methods. Finally, based on this methodology, a system for measuring instrument performance evaluation and failure early warning is constructed. Through experiments on actual total station verification data, the developed system effectively achieves performance evaluation and failure prediction for total stations.

Parameter Calibration and Verification of Spoofing Satellite Navigation Interference Simulation Source

HU Hao, LIU Hanyao, LIU Wei, SU Ze

2024, 68(9): 13-19, 67. doi: 10.12338/j.issn.2096-9015.2024.0114

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With the rapid development of satellite navigation technology, satellite navigation interference simulation sources are widely used in various applications, including unmanned aerial vehicle (UAV) countermeasures and anti-interference equipment testing and evaluation. This paper focuses on the basic functions and main parameters of spoofing satellite navigation interference simulation sources. Referencing relevant standards and specifications, we conduct an in-depth study on the parameter calibration methods for these sources. We propose calibration methods for RF signals, transmission power, spectral purity, error vector magnitude, interference characteristics, and 1PPS timing error. Additionally, we perform experimental verification and analysis on different models of spoofing satellite navigation interference simulation sources. The results demonstrate that the calibration methods for various parameters are highly operable and can effectively provide scientific and rational metrological traceability for spoofing satellite navigation interference simulation sources. This research promotes the application and development of satellite navigation interference simulation sources.

Present Status of Monoenergetic Neutron Production Technology and Reference Radiation Fields

LI Fan, ZHANG Hui, WANG Pingquan, ZHANG Yanan

2024, 68(9): 20-31. doi: 10.12338/j.issn.2096-9015.2024.0059

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Neutrons are essential tools for studying nuclear structure, nuclear reaction laws, particle physics, astrophysics, and material structure. They are widely applied in fields such as energy, materials, life sciences, medical health, radiation protection, and semiconductors. Monoenergetic neutrons, in particular, play an increasingly crucial role in ionizing radiation metrology and nuclear energy applications. Consequently, national metrology institutes and nuclear research facilities worldwide have established monoenergetic neutron reference radiation fields. The National Institute of Metrology, China (NIM) plans to construct such a facility within the next 3 to 5 years to enhance China's neutron metrology system, conduct fundamental neutron physics research, and meet the diverse needs for monoenergetic neutrons across various sectors. Based on the latest ISO 8529-1:2021 standard and in response to NIM's requirements for building a monoenergetic neutron reference radiation field, this paper reviews and calculates parameters for the five most common nuclear reactions used in monoenergetic neutron production. These parameters include neutron energy, neutron yield, neutron angular distribution, and accompanying γ-ray background. The paper also summarizes the current status and characteristics of existing monoenergetic neutron reference radiation fields, introduces the primary equipment commonly used in these fields, and provides important parameters for the proposed monoenergetic neutron reference radiation field at NIM.

A Review of Laser Multilateration Coordinate Measurement Systems and Their Development Status

ZHANG Qingyan, LI Jianshuang, MIAO Dongjing

2024, 68(9): 32-40, 60. doi: 10.12338/j.issn.2096-9015.2024.0100

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Laser multilateration coordinate measurement systems have gained significant attention from academia, industry, and metrology institutions worldwide due to their high coordinate measurement accuracy. However, the accuracy of coordinate measurement in large spatial ranges is affected by various factors, and there is a lack of domestic standards related to the measurement and calibration of these systems in China. Consequently, the development of laser multilateration coordinate measurement systems still faces numerous challenges that need to be addressed. This review comprehensively examines and summarizes the principles of laser multilateration measurement, system parameter self-calibration methods, coordinate measurement traceability status and related standard formulation, measurement uncertainty assessment and analysis of influencing factors, the extension of laser multilateration coordinate measurement in attitude measurement, and its practical applications in industrial fields both domestically and abroad. Researchers have made various attempts to improve measurement accuracy, such as compensating for environmental field interference, reducing ranging errors, enhancing system self-calibration accuracy, increasing the number of measurement stations, setting constraints, and investigating optimal system layouts. Furthermore, establishing and improving relevant standards for domestic laser multilateration coordinate measurement systems, calibration, and traceability can provide references and a basis for manufacturing and assembly of large components in industrial applications, as well as instrument calibration and compensation. This review focuses on the principles of laser multilateration coordinate measurement, system parameter self-calibration methods, coordinate measurement uncertainty, and applications. It aims to provide researchers with insights into the current development status and future trends of laser multilateration coordinate measurement systems, thereby promoting the advancement of coordinate measurement technology in large spatial ranges.

Advances in Measurement Techniques and Standardization of Alzheimer's Disease Biomarkers

ZHOU Xirui, GU Renji, MA Ruimin, JIANG Wencan, LUO Shizhong, FENG Liuxing

2024, 68(9): 41-50. doi: 10.12338/j.issn.2096-9015.2024.0054

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Alzheimer's disease (AD) is an irreversible neurodegenerative disorder highly prevalent in the elderly population aged 65 and above. With increasing global population aging, AD has become a major issue affecting public health and social development worldwide. The pathogenesis of AD remains unclear, and currently, there are no effective drugs to reverse or prevent disease progression. Utilizing a comprehensive and highly specific combination of diagnostic biomarkers for early AD detection is crucial for precise diagnosis and a prerequisite for effective treatment. Developing highly sensitive, accurate, and high-throughput quantitative techniques for AD diagnostic biomarkers is an effective approach to obtain reliable results and meets the urgent need for clinical AD diagnosis. Promoting the standardization of AD diagnostic biomarker-related tests can significantly improve the consistency, interchangeability, and traceability of results obtained from different detection platforms. This review outlines the evolution of AD diagnostic criteria and the current status of drug development, lists important disease-related diagnostic biomarkers, introduces and compares relevant measurement and detection techniques, and finally analyzes and prospects the standardization status of precise measurement techniques for AD diagnostic biomarkers. We aim to provide valuable guidance for promoting the development of related reference materials and the establishment of reference measurement procedures, as well as improving the performance of in vitro diagnostic (IVD) products and platforms in this field.

Development of a Pure Manganese Flake Reference Material for Manganese Content Calibration in X-ray Energy/Wave Dispersive Spectrometers

TIAN Donghui, SHEN Yanfei, WANG Zhigang, CHEN Yaling, HU Gang, ZHOU Zhou, PU Cheng, LIU Ping, LIU Wenjun, SHI Yunxiao, LI Xu

2024, 68(9): 51-60. doi: 10.12338/j.issn.2096-9015.2024.0053

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A reference material of pure manganese flake for manganese content calibration in X-ray energy/wavelength dispersive spectrometers (EDS/WDS) was developed. The homogeneity and stability of manganese content in the pure manganese flake were examined using electron probe microanalysis (EPMA). The manganese content (mass fraction, %) of the reference material was determined using inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). The uncertainties of the reference material were evaluated. The results show that the pure manganese flake reference material exhibits good homogeneity and stability in manganese content. The certified value of manganese content in the reference material is 99.48% with an expanded uncertainty of 0.92% (k=2). The developed pure manganese flake reference material for EDS/WDS calibration can meet the calibration requirements of EDS/WDS and provide technical support for manganese element analysis in scientific research and industry in China.

Development and Experimental Study of an Automatic Verification Device for Alpha and Beta Surface Contamination Monitors

LIU Meiling, YAO Xinbo, SUN Changhao, ZHANG Zhenzhen, JIANG Kai, LI Hongnan, MAO Chuanlin, LIANG Juncheng

2024, 68(9): 61-67. doi: 10.12338/j.issn.2096-9015.2023.0361

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To enhance the efficiency and accuracy of instrument verification and reduce the impact of manual operation, reading, and recording on verification results of alpha and beta surface contamination monitors, an automatic verification device was developed based on automation technology and machine vision algorithms. The device comprises a double-layer source-changing turntable, image training software based on machine vision technology, and automatic verification control software written in C#. The verification process, hardware structure, and software were optimized, and an algorithm for identifying abnormal results was incorporated into the software. This algorithm can perform conditional filtering and abnormal data elimination based on the characteristics of the target recognition area, improving the accuracy of optical character recognition (OCR). Performance tests, including recognition rate testing, background influence testing, comparative testing, and automatic verification process testing, were conducted. Results show that the device achieves a 100% recognition rate for original data, with no additional background interference from the centralized placement of planar sources within the device. The maximum relative deviation of measurement results between manual positioning brackets and the automatic verification device is -6.0%, showing good consistency within the uncertainty range. While meeting the requirements of JJG 478-2016, this device optimizes radiation protection and inherent source safety, significantly improving verification efficiency.

Design and Implementation of a Remote Online Calibration Platform for Power Quality Analyzers

YU Zhun, YANG Guangyi, LIU Huichao

2024, 68(9): 68-72. doi: 10.12338/j.issn.2096-9015.2024.0160

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In response to the current limitations in calibrating power quality analyzers, which typically require sending equipment to professional institutions for metrological traceability—a process that is not only time-consuming and labor-intensive but also fails to evaluate measurement performance under actual operating conditions—we have developed a remote online calibration platform for power quality analyzers. This innovative platform integrates network technology, measurement technology, and communication technology, leveraging the Internet of Things, cloud services, and encryption techniques to establish a comprehensive remote calibration process. The system enables real-time control of standard instruments and devices under calibration, facilitates automatic data collection and processing, and generates calibration certificates autonomously. With this platform, users anywhere can simply power on the standard instrument and the device under calibration, connect the necessary data cables and network, allowing superior metrological technical institutions to remotely conduct the entire calibration process, ensuring full control and oversight throughout. Experimental tests have demonstrated that this remote online calibration platform offers high calibration accuracy and user-friendly operation, presenting broad application prospects in the field of power quality measurement and smart grid technologies.

2024 Vol. 68, No. 9

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